SEASONAL DYNAMICS OF NITROGEN IN CULTIVATED SOIL AT GIAO THUY DISTRICT, NAM DINH PROVINCE

This paper focuses on evaluating the nitrogen mineralization and NH4+ and NO3- leaching from the root zone in cultivated soils of Giao Thuy district, Nam Dinh province using Synthetic accumulation (SIA) method. Main findings reveal that total N content in vegetable fields and rice-vegetable-rotational fields ranges from 17.68 – 113.68 kgN ha-1, and from 14.64 – 132.59 kgN ha-1, respectively. Total N is also significantly different between saline paddy-fields and fresh-water fields, varies between 16.33 – 82.12 kgN ha-1 and from 23.89 – 74.04 kgN ha-1, respectively. NO3- accounts for a larger proportion in vegetable fields and accumulated higher during the dry season; NH4+ predominates in paddy fields and accumulated mainly in rainy season. The N leaching losses decreased in the following order: vegetable, rice-vegetable rotation, non-saline and saline soil.

CONTAMINATION BY PERSISTENT ORGANIC POLLUTANTS AND ENDOCRINE DISRUPTING CHEMICALS IN VIETNAM : PATTERNS, BEHAVIOR, TRENDS AND TOXIC POTENTIAL

Joint Research on Environmental Science and Technology for the Eart

Morphological characterization and classification of cassava (Manihot esculenta Crantz) in Vietnam

The aim of this study was to establish the morphological basis for the classification of major cassava cultivars (Manihot esculenta Crantz) planted in Vietnam. Twenty typical descriptors were observed in various specific growth stages. Four traits related to mature leaves and two traits related to leaf veins were detected in cassava plant after the 4-month stage. At the same time, 12 root- and stem-related descriptors were collected in cassava plants from 8-months to harvest. We found that two traits in the apical leaves can be observed in every growth stage. A classification tree based on these traits was constructed with 6 essential morphological descriptors to recognize the 7 most common cassava cultivars in Vietnam. KM 140 variety is distinguished by purplish-red in apical leaves, while KM 98-7 can be classified with straight or linear shapes of central leaflet. The irregular orientation of the petiole is a unique descriptor of local cultivar XVP. In the case of SM 937-26, weak foliar scars are observed. Finally, KM 94, KM 419, and KM 98-5 varieties can be classified by the color of the stem epidermis. These morphological descriptors will be a foundation to classify all cassava varieties planted in Vietnam.

Chemical composition and cytotoxic activity of the essential oils of Cymbopogon citratus L. Grown in phu tho province

Culms and leaves of Cymbopogon citratus L. were collected from two regions of Phu Tho province (Thanh Son and Phu Ninh) and used as materials for essential oil extraction. Oils obtained were steam-distilled, analyzed for chemical composition and evaluated for cytotoxic activity against three different cancer cell lines. The GC/MS analysis showed that citral is the major content of the steam-distilled essential oils which was found in the range of 64.15-76.22%. Camphene was found only in culm oils of both regions but it was not detected in the leaf oils. Interestingly, the isomer forms of ocimene present at higher content in the culm oils than in the leaf oils whereas myrcene content in the leaf oils is higher than that in the culm oils. In a cytotoxicity test, four essential oils of culms and leaves of C. citratus from Thanh Son and Phu Ninh showed potent activity against A549 (human lung carcinoma) cell line with the IC50 values ranging from 4.01±0.39 to 6.3±0.54 µg/ml. The essential oils (culms and leaves) from Phu Ninh exhibited moderate effects on the Hela (human cervical adenocarcinoma) cells with the IC50 values of 19.43±1.16 and 42±2.41 µg/ml, respectively. However, they were inactive against the human hepatocellular carcinoma Hep3B cell line. The essential oils from Thanh Son exhibited potent cytotoxic activity against Hela and Hep3B cell lines with the IC50 values ranging from 1.18±0.26 to 8.91±0.32 µg/ml. The results indicated that the essential oils of C. citratus from Thanh Son, Phu Tho could be considered as a promising candidate for the natural sources of anticancer agents

A Multi-Center Randomized Trial to Assess the Efficacy of Gatifloxacin versus Ciprofloxacin for the Treatment of Shigellosis in Vietnamese Children

The bacterial genus Shigella is the most common cause of dysentery (diarrhea containing blood and/or mucus) and the disease is common in developing countries with limitations in sanitation. Children are most at risk of infection and frequently require hospitalization and antimicrobial therapy. The WHO currently recommends the fluoroquinolone, ciprofloxacin, for the treatment of childhood Shigella infections. In recent years there has been a sharp increase in the number of organisms that exhibit resistance to nalidixic acid (an antimicrobial related to ciprofloxacin), corresponding with reduced susceptibility to ciprofloxacin. We hypothesized that infections with Shigella strains that demonstrate resistance to nalidixic acid may prevent effective treatment with ciprofloxacin. We performed a randomized controlled trial to compare 3 day ciprofloxacin therapy with 3 days of gatifloxacin, a newer generation fluoroquinolone with greater activity than ciprofloxacin. We measured treatment failure and time to the cessation of individual disease symptoms in 249 children with dysentery treated with gatifloxacin and 245 treated with ciprofloxacin. We could identify no significant differences in treatment failure between the two groups or in time to the cessation of individual symptoms. We conclude that, in Vietnam, ciprofloxacin and gatifloxacin are similarly effective for the treatment of acute dysentery

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Distribution of Nemipterus marginatus (Valenciennes, 1830) (Nemipteridae, Perciformes) in the estuary and coastal areas of North Central, Vietnam

We provide data on morphological characteristics and the distribution of the nemipterid fish Nemipterus marginatus (Valenciennes, 1830) in the estuary and coastal area of Thanh Hoa province, North Central Vietnam. This is also a clear location record for the distribution of this species in the North Central region compared to previous studies, and a new record for the study area

RP-HPLC and UV Spectrophotometric Analysis of Paracetamol, Ibuprofen, and Caffeine in Solid Pharmaceutical Dosage Forms by Derivative, Fourier, and Wavelet Transforms: A Comparison Study

Different signal-transforming algorithms were applied for UV spectrophotometric analysis of paracetamol, ibuprofen, and caffeine in ternary mixtures. Phosphate buffer pH 7.2 was used as the spectrophotometric solvent. Severe overlapping spectra could be resolved into individual bands in the range of wavelengths 200–300 nm by using Savitzky–Golay smoothing and differentiation, trigonometric Fourier series, and mother wavelet functions (i.e., sym6, haar, coif3, and mexh). To optimize spectral recoveries, the concentration of various types of divisors (single, double, and successive) was tested. The developed spectrophotometric methods showed linearity over the ranges 20–40 mg/L for paracetamol, 12–32 mg/L for ibuprofen, and 1–3.5 mg/L for caffeine (R2 > 0.990). They could be successfully applied to the assay and dissolution test of paracetamol, ibuprofen, and caffeine in their combined tablets and capsules, with accuracy (99.1–101.5% recovery) and precision (RSD 0.05, suggesting possible interchange between UV spectrophotometric and HPLC methods for routine analysis of paracetamol, ibuprofen, and caffeine in their solid pharmaceutical dosage forms